Apple began supplying prerelease builds of OS X 10.8.5 Mountain Lion to select partners on Monday, signaling that a public release of the maintenance and software update is not far behind.

People familiar with the software indicated to AppleInsider that the prerelease version made available is identified as build "12F35." The update, recommended for all users of Mountain Lion, includes the following changes:

Fixes an issue that may prevent Mail from displaying messages

Improves AFP file transfer performance over 802.11ac Wi-Fi

Resolves an issue that may prevent a screen saver from starting automatically

Improves Xsan reliability

The prerelease build supplied to partners on Monday is said to weigh in at 286 megabytes. Those early releases are typically provided only hours before the software is launched to the public, suggesting that OS X 10.8.5 will arrive on Monday.

A total of seven beta builds of OS X 10.8.5 have been supplied to developers for testing ahead of the final release. The most recent was issued on July 31, identified as build "12F30."